While the labels themselves are just markers, the technology behind the headers they represent differs significantly: USB_E12 (Typically Gen 1) USB_E34 (Typically Gen 2/USB4) 10 Gbps - 40 Gbps Common Protocol USB 3.2 Gen 1 USB 3.2 Gen 2 / USB4 Best Use Case Keyboards, Mice, Basic USB Drives External SSDs, 4K Video Editing Power Delivery Standard (up to 4.5W-100W with PD) High (up to 100W-240W) Which One Should You Use? How to Identify Different USB Types: A Brief Guide - Anker